Method of and apparatus for making grids



Dec. 24, 1940. c. LBAKER r-:TAL

` METHO'D 0F AND APPARATUS FOR MAKING GRIDS Filed Dec. 13, 1938 3 Sheets-Sheet 1 A Tron/VEP METHOD F AND APPARATUS FOR MAKING GRIDS Filed Dec. l5, 1938 3 Sheets-Sheet 2 C. l. INVENTORS @A KER o. @A mrs@ w. MA URER EAR MW A TTOR/VE V De@ 24, 1940- c. BAKER ET AL 2,225,853

METHOD OF AND APPARATUS FOR MAKING GRIDS Filed Dec. 13, 1938 5 Sheets-Sheet 5 ll WIW c. i. @A frm /NVENTORS l/.QBARKR 8 c. wml/RER A TTORNEV Patented 24, 1940 UNITED'. STATES' METHOD F AND APPARATUS FOB MAKING GRIDS Carl I. Baker, Pearl River, N. YL.' Virgil D. Barker, Westfield, N. J., and Carl W, Maurer,

Freeport, N. i.,

aasignors to Western Electric Company, Incorporated, New York-N. Y., a corporation of New York sppnesnen peeeniber 1a, 193s, semi Ne. 245,41s 17 claims. (ci. z's-ss) This invention relates to ak method of and apparatus for making grids, and more particularly to a method of and apparatus for making vacuum tube grids.

l Grids for vacuum tubes have been formed by welding the grid wiresto their supports. In thus welding the wires much care must be taken to Vform a satisfactory connection and avoid burning of the wires. Even then it is diiiicult to form a grid# having uniformity of contour.

Grids for vacuum'tubes have also been formed by windingja grid wire about 'spaced notched bars,

the latter being swaged to grip the convolutions of the wires.

dimeuuy nes been found 'in forming Smau grids.

Objects of the invention are-to provide a simple and emcient method of' and apparatus for l making grids without employing welding 'as a securing means between the grid wires and their supports.

With 'these and other objects in view, the in:

vention comprises an apparatus by the aid of which a method may be practised by advancing round parallel bars, forming notches therein, placinglateral grid wires in the notches, swaging the bars to lock the wires in place, pressing the barsilat, severing portions of the flat bars and forming the. severed portions into circular heads. Other objects and advantages will be apparent 3o remtne renewing leaned descr-innen tekenm conjunction with the accompanying drawings. wherein j Fig. lis a side elevational view partially in section of the apparatus by the aid of which a 35 method may be practised;

Fig. 2 is a top plan view of the apparatus; Fig. 3 is an enlarged fragmentary sectional view taken along the line 3-3 of Fig. 1;

Fig. 4 is a fragmentary detailed view taken 4o substantially along' the line 4--4 of Fig. 1;

a suitable support (not shown) and has spaced 50 projections I2 to removably receive and support a shaft I3 for a pair of supply reels I4. The supply reels Il are relatively-narrowin width, so as to supply round'bars I5 to the apparatus inV substantially equally spaced parallel relation.

55 Suitable means, such as a guide it, having spaced apertures l1 therein, is-mounted upon the frame Il to guide the bars 'I5 in their predetermined spaced relationship during advancement.

Means for advancing the bars consists of a 60 serrated roller I8 fixedly mounted upon a hollow In forming grids in'this manner shaft I9 and driven at a predetermined speed in a clockwise direction. A shaft 20 extending through bearings lin the vertical walls of the frame I0 and through the hollow shaft I9 is y operatively connected to a power means (not 45 shown) through a friction clutch 2'I, or other suitable means, and a gear 22. A chain of gears 23, 24, 25fand 26 operatively connects the shaft 2li to the hollow 'shaft I9, the gears 2l and 25 being nxemy mounted upon n shaft 21 jour-nailed 10 in bearings inthe frame whilethe gear- 23 is fixed to the shaft 20 and the gear 26 is fixed to the hollow shaft I9. A second, yet still more important, function of the serrated roller I8 is to form equally spaced notches in the upper por- 15 tions ofthe bars, the notches in one bar being in alignment with the notches of the other. To assist the serrated roller informing the notches in the bars and limiting the depth of these notches, an idler roller 28 is mounted upon a 20 'shaft 29 and rotatably journalled in the frame I0. There are intervals during the operation of the apparatus when there should be 'a pause in the advancement of the bars. This may be taken -care of through the friction clutch 2 I. 25 After the bars I5 have been notched, a predetermined number of grid wires 30 may be fed across the bars and laid in successive aligned notches therein. In the present embodiment of the invention the article to be formed, as illus- 30- trated in Fig. 8 has six grid wires therein and these wires, supplied from six different supply reels (not shown), may be fed as a group manually, or if desired a suitable mechanically actuated arm may be employed to automatically feed the wires into the notches of the bars.

After the wires have been fed into their respective notches a reciprocable element 3| (Figs. l, 2 and 4)-.fhaving a knife 32 mounted thereupon and positioned to be moved into engage- 40. ment with a cooperating cutting member 34 iixed to the frame I0, is conditionedto be moved downwardly to sever the wires. The element 3l also has a at under surface 35 positioned to strike the upper surfaces of the bars over the wires disposed therein to partially swage the bars, as illustrated in Fig. 5, to secure the wires against displacement. The element 3| is slidably dis.

posed in a/guideway 3l fixed to the frame I Il' and spaced from the bars a suillcient distance to allow, feeding of the wires therebeneath. Reciprocatory movement is imparted tothe element -3I by mechanism operatively connecting it to the shaft 20. This mechanism consists of a link 3-8 `pivotally connected at one end to the element Il and at the other end to a gear 39. Theconn ection of the link 38 with the gear 39 is eccentric with respect to the axis of rotationof the gear so as to cause a complete cycle of reciprocatory movement of the element 3l during each 60 rotary cycle of the gear. The gear 39 is mounted rotatably upon a stub shaft 40 carried by -the frame I andinterengages a gear 42 :dxedlyV mounted upon the shaft 21. .'Iherefore, during 5 rotation ofthe shaft 20 power is transmitted through gears 23 and`24 through shaft 28, gears 42 and 39, and link 38 to the element 3|.

After the grid wires 30 have been fed to the notches in the bars and have been severed by the knife 32 and held against displacement by the partial swaging of thebars caused by the element 3|, the bars l5 with the lateral grid wires are advanced between pre-pressing rollers 50, which are mounted upon shafts 5| journalled in bearings of the frame I0. In passing between the ro1lers50 the bars I5 are further pressed, yet the bars receive their nal pressing and forming at the next position, namely a position beneath a reciprocable forming element 53. 2D The forming element 53 is slidable vertically in guideways 54 carried by the frame I0 and has a flat under surface of suiiicient width to extend across both bars |5 and of suflicient thickness to form portions of the bars of equal or greater lengths than required for each article. An abutting block 55 mounted in a recessed portion of the framey I0 is positioned to supportrthe bars while they are beingformed. The operation of the forming element 53 will hereinafter be described.

I'he bars I5 are advanced from the forming position beneath the element 53 to a position where predetermined lengths thereof are positioned between a cutting and forming unit 51. In the present embodiment of the invention the article being formed is shown with six lateral or grid wires therein. Therefore, the bars I5 are advanced to position lengths thereof having six lateral wires therein beyond the` edge of a 40 cutting knife 58 prior to actuation of the unit 51 upon which the knife is mounted. The unit 51 is composed of three parts in addition to the cutting knife 58, these parts consisting of a stationary forming and shearing die 60, a movable forming die 64, and a core 68. 'I'he stationary forming die has a semi-circular concave groove 6|- in the upper surface thereof and'a slot 62 positioned to receive the knife 58 and to provide a shearing surface cooperating with the knife in severing portions from the bars. The stationary die 60 is mounted in a suitable recess of the frame I0. The movable forming die 54 has a semi-circular concave recess 85 in the lower surface thereof positioned to cooperate with the re- 55 cess 6| in the stationary forming die 60 to form the portions of the bars I5 in circular formation. The third portion of the unit 51, namely, the core 68, is rigidly carried by a block 69` and positioned to extend between the grooves 6I and 65 of the dies 60 and 64. The block 69 is slidably disposed in a suitable guideway and 'is normally urged downwardly by a helical spring 10 disposed concentric with a rod 1I and partially embedded in a recess 12 in an offset portion of the die portion 64. The rod 1| has its lower end extending through and xed to the block 69 and extends vertically through an aperture 14 to a position-above the die member 64, where it is provided with a head portion 15, the pur- 70 pose of the head portion being to limit the downward movement of the core 68 by the spring 10. The forming element 53 and the unit 51 have vertically extending projections and 8|, respetively, with pins 82 in their upper ends ex- ?F. tending laterally therefrom and positioned in a termined length from the bars.

transversely extending cam slot 83 of an actuating cam '84. The actuating cam 84 is slidable in guideways 85 of the frame I0 and has its inner end supporting a connecting rod 81 (Figs. 1 and 2). The connecting rod 81 extends through 5 an elongate aperture 'in the adjacent wall of the frame I0 and has disposed thereon a roller 9| positioned to ride between and upon the parallel walls of the aperture 80 during reciprocatory movement of the cam 84. Recipro- 10 catory movement is imparted to the cam through a link 93, having one end mounted upon the connecting rod 81 and the other end connected eccentrically at 94 to a wheel 95, the latter being xed to the shaft 21.

During operation of the apparatus in carrying out the various steps of the method to lproduce the article the apparatus is set in motion, causing rotation of the serrated roller I9 to advance the bars from their supply reels I4 to the aper- 20 ture I1 in the guide I6.

As the bars I5 pass between the serrated roller I8 and the idler roller 28 aligned grooves or notches are formed' in the upper portions thereof. In forming the notches in the bars the ex- 25 cess material, disturbed by the projections of the serrated roller, moves upwardly to allow notches for receiving the lateral grid wires 30, which material will be partially pressed around the wires during the actuation of the element 30 3|. At this, the second position, beneath the element 3|, the grid wires are severed by the actuation of the knife 32 and each wire is vclamped in place by the partial swaging of the disturbed material of the bars therearound, as 85 illustrated in Fig. 5. The bars and the lateral grid wires are advanced between the rollers 50, where the disturbed material of the bars is further pressed about the grid wires. The bars are finally attened when they are positioned Vbe- 40 neath the forming element 53 and when they are advanced a sufhcient distance relative to the forming unit 51, portions of predetermined lengths are severed from the bars by the knife 58, which portions contain a desired number of 45 lateral grid lwires to be included in the completed article. 'I'he article is completed in the forming unit which, during the downward movement thereof, iirst severs the portions of prede- Durng further 50 downward movement of the unit these severed portions are engaged by the core 68 which, by the force of the downward movement of the unit, will cause the bar portions to be pressed into the concave recess 6I of the stationary die 55 60, forming the portions into substantially U- shapewiththe ends thereof extending vertically upon each side, of the core. Further downward movement of the unit 51 will cause compression of the spring 10, which has been of suf- 60 cient force to cause the core 68 to partially form the bar portions. This further downward movement of the unit 51 will bring the movable die portion 64 downwardly until it engages the upper surface of the stationary die, causing the 65 ends of the bar portions to be brought together to complete the circularvformatlon of the bar portions about the core, as illustrated in Figs. 2, 3 and 7. Upward movement of the unit 51 will free the movable die 64 from the stationary 70 die 60 and the force of the spring 10 limited by the head 15 will move the rod 1| to position the core 68 holding the finished grid or article between the dies 50 and 64 in their open position so that the article may be readily removed 75 from the core manually or by any suitable mechanical means.

The results of the various elements on the bars during the processing thereof through the apparatus have been described, and now attention is directed to the operating mechanism for controlling these elements. The serrated roller is driven from a power means (not shown) through the gear 22 and the friction clutch 2| or other suitable connecting means. To drive the serrated roller at a desired speed determined by the number of lateral grid wires desired for each article, thelspeed of rotation of the ser-4 rated roller is reduced byconnecting the roller to the hollow shaft I9 and through this shaft to the driven shaft2 by means of the gears 23,

' 2l, 2l and 26.

' The element 3| is connected to the power means through gears 39, l2, shaft `2", and gears 24 and 2l. mus rotation of the gear Il, as illustrated in Pigs. 1 and 4, will cause reciprocatory move# ment to be imparted to the element through thelink I8.

The rollers Sh are not driven by the power means but are rotated by the passage of .the bars therebetween.

The forming-'element and the unit 51 are actuated by the same operating means, namelythe movement of the cam 84, which 'is'brought about by rotation of the wheel $5, the' power of which is traced to the shaft 2 0 throughthe shaft 21, gear 2l, and gear ,23, causing reoiprocation of the cam through the link l! 4to move the cam slot 82 relative to the'pins 3 2. ':'I he cam Il is shown in Fig. 4 in the lower position, in which position the element 53 and the unit 51 have completed their work. Movement of the cam Il upwardly causes the' cam slot or aperture 83 to move the forming'element and unit upwardly.

The article formedby the apparatus and by` following the steps of the method ,is composed of cylindrical collars, fabricated from round bars andpressed into at or substantially rectangular cross-sectional formation, with the grid wires liirmly embedded therein, eliminating the necessity of welding the wires tothe collars and the damage which might occur to thecollars and J wires as a result of welding.

The embodiments of the `invention herein disclosed are illustrative only vand may be widely modified and departed from in many ways without departing from thespirit and scopeof the invention as pointed out in and limited only by the appended claims. f,

What is claimed is:

1. A method of making grids comprising forming grooves in bars, feeding grid wires to the grooves, and swaging the bars to secure the.

wires therein.

2. A method of making grids comprising forming grooves in bars, feeding grid wires to`the grooves, swaging the bars to secure the wires therein, and forming the bars circularly.

3. A method of making grids comprising forming grooves in bars, feeding grid wires to the grooves. and iiattening the. bars to embed the wirestherein.`

4. A method of making grids comprising forming 'grooves inbars, feeding grid wires to the lgrooves from supplies, severing predetermined lengths of wires from the supplies, and swaging the bars to secure the wires therein.

5. A method of making grids comprising formin! grooves in bars, feeding grid wires to the the bars.

grooves from supplies, and simultaneously severing predetermined lengths of wires from the supplies and swaging the bars to securethe wiresy therein.

6. A method of making grids comprisinggforming 'grooves in round rods, feeding grid wires to the grooves, and flattening the rods to embed the wires therein.

7. A method of makinggrids comprising forming grooves in bars, limiting the depth of the' grooves during' forming thereof, feeding gridwires to the grooves, and. swaging the bars to secure the wires therein.

48. A method of making grids comprising forming grooves in barsyfeeding grid wiresA to the grooves from supplies, severing predetermined lengths of wires .from the supplies, severing portions from the bars, and forming the portions.

9. In an apparatus for making grids, means swage the bars to secure the wires to the bars.

10. In van apparatus for making grids, means I for advancing spaced bars, means to form grooves in the bars to receive grid wires, means to swage the bars tosecure the wires to the bars, and means to sever portions of predetermined length from thebars.'

1l. In an apparatus for making grids, means for advancing spaced bars, means to form grooves in the bars to receive grid wires, means to swage the bars to secure the wires to the bars, means to sever portions of predetermined length from the bars, and means to cause\circul ar forming of the bars. 12. In an apparatus for making grids, means for advancing spaced bars in parallel relation.

means to form grooves in the bars to receive grid wires, and means to swage the bars to secure 40 the wires to the bars.

13. In an apparatus for making grids, means foradvancing spaced round bars, means to form grooves in the bars to receive grid wires, and

for advancing spaced round bars, means to form grooves in thebars in receive grid wires, means to flatten the bars to embed the .ends of the wires therein, means to cause circular form- `ving of the bars, and means` to sever portions o! predetermined length from the bars.

16. In an apparatus for making grids, means for advancing spaced round bars, means to form grooves in the bars to receive grid wires, means to ilatten the bars to embed thev ends of the wires therein, means to cause circular forming of the bars, and means to sever portions of predetermined length from the bars and complete the forming of the portions.

1'?. In an apparatus for making grids, means for advancing bars, means to form grooves in the Abars to receive grid wires, means to sever the grid wires into predetermined lengths, and means to swage the bars to secure the wires vto CARL r. BAKER.

man. n. naam. om w. moana.

. means to iiatten the bars to embed the ends of 

